MP4 is an extension defined by MPEG-4 video standard and AAC audio standard. It is a container that supports all kinds of media such as video, audio, subtitles, 2D and 3D graphics. It is possible to open MP4 file with almost any player on Windows but on Mac you should use a plug-in or just convert the file to another format.

8-Bit Sampled Voice (8SVX) is an audio file format standard developed by Electronic Arts for the Commodore-Amiga computer series. It is a data subtype of the IFF file container format. It typically contains linear pulse-code modulation (LPCM) digital audio. The 8SVX subtype stores 8-bit audio data within chunks contained within an IFF file container. 8SVX subtypes can exist alone within IFF file containers (audio only), or can be multiplexed together with other IFF subtypes, such as video animation streams.